import sys
from PyQt5.QtWidgets import QWidget,QApplication
from PyQt5.QtGui import QPainter,QColor,QBrush

class Example(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setGeometry(300,300,350,100)
        self.setWindowTitle('Colors')
        self.show()

    def paintEvent(self,e):
        qp = QPainter()
        qp.begin(self)
        self.drawRectangles(qp)
        qp.end()

    def drawRectangles(self,qp):
        col = QColor(0,0,0)
        col.setNamedColor('#d4d4d4')
        qp.setPen(col)

        qp.setBrush(QColor(200,0,0))
        qp.drawRect(10,15,90,60)

        qp.setBrush(QColor(255,80,0,160))
        qp.drawRect(130,15,90,60)

        qp.setBrush(QColor(25, 0, 90, 200))
        qp.drawRect(250, 15, 90, 60)

if __name__=='__main__':
    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())